1. Field of the Invention
The present invention concerns detergent compositions. More particularly, the present invention concerns stable detergents in the form of emulsions. The present invention also concerns stable detergent emulsion compositions which contain unusually low and high levels of nonionice surfactants. Even more particularly, the present invention pertains to detergent emulsions containing components which are stable in highly caustic environments.
2. Description of Relevant Art
Stable detergent emulsions have long been known. Conventionally, these emulsions are prepared by mixing together selected nonionic surfactants, with or without detergent "builders", and a partially esterified maleic acid copolymer which is used to stabilize the active organic ingredient in the aqueous phase. The use of the partially esterified maleic acid copolymer is described in U.S. Pat. No. 3,591,508.
One major problem inherent in the use of partially esterified maleic acid copolymer stabilizers is the instability of such stabilizers in highly alkaline solutions. The addition of salts of alkali metals to compositions containing such stabilizers triggers their hydrolysis to non-useful forms.
It is to be appreciated through, that prior art detergent emulsions contain relatively low levels of nonionic surfactant as the active organic ingredient. Conventionally, system limitations inherently preclude the incorporation of greater than about fifteen percent, by weight, of active organic ingredient. Ordinarily, nonionic surfactants are present in such emulsions in a range of about five to fifteen percent. Above this level of active organic ingredient, instability of the system occurs. This precludes the employment of such emulsions in heavy industrial usage, such as industrial laundries.
As is known to those skilled in the art to which the present invention pertains, conventionally, elevated levels or organic ingredient are necessary in industrial laundries. Based upon recent technology, many industrial laundries employ powder detergents since these contain greater than twenty-five percent, by weight, of nonionic surfactant. Currently, where liquid build detergents are used, the laundries employ an admixture of a liquid nonionic surfactant dispersed in a solvent, which is commonly referred to as a "nonionic oil". Then, separately, and apart from the liquid system there is added to the laundry a liquid "builder", in order to enhance detergency. Based upon the disparity of percentages of active ingredient between liquids and powders it is most difficult for a liquid built detergent to compete with a powder built detergent in industrial laundry usage, both from cleaning ability and economy of use.
As will subsequently be detailed, the present invention overcomes the lower level active ingredient problem in the prior art by providing liquid detergent emulsions which have unusually high levels of nonionic surfactant incorporation therewith.